Of receding glaciers and lack of benchmark data

Prof. Syed Iqbal Hasnain at Khardungla. Locals say the glacier here has retreated. - PHOTO: MEENA MENON  

From Leh, the 40-km drive to Khardungla, the highest motorable pass in the world at 18,380 feet, winds gently through mountains coated with thick snow. To the left of the pass the Ladakhis swear is the Khardung glacier which has retreated, though there is no study to confirm it. In fact, Prof. Syed Iqbal Hasnain, a leading glaciologist and a senior fellow at The Energy and Resources Institute (TERI) who visited Khardungla along with a group of journalists recently, did not know of its existence. Local wisdom differs. Small glaciers in Ladakh have receded over the years and some them could well be the subject of history.

There is an acute lack of benchmark data on small glaciers, which is why Prof. Hasnain has undertaken this task, not without some difficulty. Trained mountaineers have been requisitioned to help study some smaller glaciers in different Himalayan regions, some of them steep and inaccessible. "In the last 60 years, we don't have any benchmark glacier studies. Gangotri is too large to be a benchmark glacier," he points out.

Inspired by Prof. V. Ramanathan's study on the Atmospheric Brown Clouds and the role of black carbon, Prof. Hasnain is now measuring black carbon on glaciers with the help of aethalometres. At a recent presentation before journalists in Leh, he spoke of the disappearing "Himalayan Ice Climate and Black Carbon Aerosol Impacts on Water resources." Leh was perhaps an apt place for this presentation, where Prof. Hasnain admitted there is very little data on what is the regional rate of glacier melt or the role of black carbon forcing and deposition.

For future climate scenarios, he says you have to develop benchmarks as also data on what is the contribution of snow glacier melt to the water flow in rivers.

Four small glaciers have been selected for this benchmark study, one each in the Zanskar, Kashmir Valley, Himachal Pradesh and Sikkim based on advice from the World Glacier Monitoring station in Zurich to study comparable glaciers which were less than 15 sq km. Already for the Kolahoi glacier in Kashmir, Prof. Hasnain found photographs dating back to 1942 which show a healthy accumulation zone where the snow collects in the glacier. "The measurements have started on black carbon, we know it is present but how much impact is there in the melting process will take a while to assess," he points out.

An aethalometer has been installed at East Rathong glacier at 4,700 metres to measure the black carbon there which is high in the Western Himalayas and this is directly related to the transport sector. The adulteration of diesel with kerosene poses a major threat to fragile environments. Some of the initial results on black carbon depositions were shown to Union Environment Minister Jairam Ramesh who has asked Prof. Hasnain to submit a project to measure yearly carbon emissions. Black carbon is an important pollutant in global warming and some policy commitment is needed before COP 15 in Copenhagen, he feels.

The impact on small glaciers has been borne out in a new study "Witnessing change: Glaciers in the Indian Himalayas," by the World Wide Fund for Nature (WWF) and the Birla Institute of Technology (BIT) Extension Centre, Jaipur. The initial results from this field study indicate that smaller glaciers like Kafni in the Kumaon region are retreating at a faster rate, and are not only losing more glaciated portion but also their tributary glaciers - a trend which has been observed across the Himalayas for many other smaller glaciers.

Larger glaciers like Gangotri which is the second glacier in this study shows a continuous recessionary trend in recent years through this and other studies (Singh, et al., 2006). Dr. Rajesh Kumar, scientific officer of the BIT, extension centre, Jaipur, part of the WWF study notes that despite the fluctuations over the years, there is a sharp retreating trend and the latest figure of retreat for the Gangotri glacier is 17.19 metres per year. Glaciers are more vulnerable to changes in temperatures and Gangotri has already retreated by 20 metres so far. However, the 29.5-km-long glacier still has breathing time.

The study concludes that regional climate variations could threaten the fragile nature of these glaciers which are likely to disappear at a much faster rate or be considerably reduced in length as compared to the larger ice bodies. Emerging trends are not a good omen for glaciers in Uttrakhand and elsewhere and need a detailed study based on more satellite imageries and ground research.

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Printable version | Jan 20, 2022 8:31:19 AM |

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